Spaceplane SAS problem

[ohlookabirdie]

so in the pics below is my SP1 - Raven atmospheric plane. it works... almost

its in career mode and i have yet to unlock the landing gears, so it takes off from the launch clamps. it does this very well (after some tweaking of the positions).

my problem now is that the SAS, instead of keeping it on course, makes my plane roll... i dont know why.

can anyone help? is SAS not meant to be used for planes?

i need it to keep it on course since the plane isnt very stable in manual flight mode (hence why i am starting it pointing north i want o explore the poles)

[Dispatcher]

I'm using SAS with planes (doing a project in sandbox). SAS works best for me when I add an inline stabilizer. For large planes I also add an RGU near the CoM, in case I want to control from it for possibly better flight results. Even without these elements, I think the design affects how well SAS does in assisting the flight. If you had screen shots in the SPH with CoM, CoL and CoT enabled, it would be easier to see what is going on with your plane. Even though it looks symmetrical, sometimes stabilization is better with a central stack along the length.

[Cal'Mihe]

Your elevators are put on the front part of the wing instead of the rear I suspect this causes the SAS a lot of confusion.

[arq]

I agree that the control surfaces on the front of the wing are likely the reason for your troubles.

[ohlookabirdie]

thanks guys i'll try to put the control surfaces on the rear of the wings... and if that doesn work i'll get you a SPH shot with the centers on

[ohlookabirdie]

ok so the control surfaces on the back side of the wings worked in stopping the roll.... now i have a new problem

the SAS cant keep the plane from pitching upwards, i guess this is because the centers of mass, thrust and lift are in the wrong places. where should they be in relation to each other? and how do you think i should fix this on my plane

here are SPH pics

[ohlookabirdie]

moved the wings back.... center of lift slightly behind and above the CoM and it works fine now, flew to the northern ice cap and did science. recovered and got 30 science points.... 30!! for all that effort